The music teacher in my highschool was a disconnected jerk who sort of looked like Stuttlemeyer or wahtever the police chief is from the show Monk is.
Anyway, when I had him freshman year, he hardly taught at all, had us copy 3 pages of notes per class and spoke of famous musicians. He let us gamble in class, flipping, dice, you name it. He would be out of class for 30 minutes at a time on the phone and he wouldn't address issues if he was in his side office area and we did whatever we wanted.
It was freaking awesome.
However, I got out of his class and two years later WASC or WASP or something of that sort came to the school to do an in depth live evaluation of each teacher. Some teachers were praised, some chastised.
That music teacher straight up disappeared. Of course there will be rumors of drugs and such, but I believe he had a gambling problem. But I will always remember the day I made $70 in three seconds.
In middle school someone selling laxatives as drugs, and then after he got jumped by 10 people he sold them as laxatives and students would spike teachers drinks and stuff with them. It took them two days to figure out what was happening. And he was expelled.